light/modules/engine/src/platform/graphics/opengl/vertex_layout.cpp

107 lines
3.8 KiB
C++

#include <engine/platform/graphics/opengl/buffers.hpp>
#include <engine/platform/graphics/opengl/vertex_layout.hpp>
#include <glad/gl.h>
namespace Light {
glVertexLayout::glVertexLayout(
const Ref<VertexBuffer>& buffer,
const std::vector<std::pair<std::string, VertexElementType>> &elements
)
: m_array_id(NULL)
{
// check
lt_assert(
std::dynamic_pointer_cast<glVertexBuffer>(buffer),
"Failed to cast 'VertexBuffer' to 'glVertexBuffer'"
);
lt_assert(!elements.empty(), "'elements' is empty");
// local
auto elementsDesc = std::vector<glVertexElementDesc> {};
elementsDesc.reserve(elements.size());
auto stride = 0u;
// extract elements desc
for (const auto &element : elements)
{
elementsDesc.push_back(get_element_desc(element.second, stride));
stride += elementsDesc.back().typeSize * elementsDesc.back().count;
}
// create vertex array
glCreateVertexArrays(1, &m_array_id);
// bind buffer and array
buffer->bind();
bind();
// enable vertex attributes
auto index = 0u;
for (const auto &elementDesc : elementsDesc)
{
glVertexAttribPointer(
index,
elementDesc.count,
elementDesc.type,
GL_FALSE,
stride,
(const void *)elementDesc.offset
);
glEnableVertexAttribArray(index++);
}
}
glVertexLayout::~glVertexLayout()
{
glDeleteVertexArrays(1, &m_array_id);
}
void glVertexLayout::bind()
{
glBindVertexArray(m_array_id);
}
void glVertexLayout::un_bind()
{
glBindVertexArray(NULL);
}
auto glVertexLayout::get_element_desc(VertexElementType type, unsigned int offset)
-> glVertexElementDesc
{
switch (type)
{
/* byte */
case Light::VertexElementType::Byte1: return { .type=GL_BYTE, .count=1u, .typeSize=sizeof(GLbyte), .offset=offset };
case Light::VertexElementType::Byte2: return { .type=GL_BYTE, .count=1u, .typeSize=sizeof(GLbyte), .offset=offset };
case Light::VertexElementType::Byte4: return { .type=GL_BYTE, .count=1u, .typeSize=sizeof(GLbyte), .offset=offset };
/* ubyte */
case Light::VertexElementType::UByte1: return { .type=GL_UNSIGNED_BYTE, .count=1u, .typeSize=sizeof(GLubyte), .offset=offset };
case Light::VertexElementType::UByte2: return { .type=GL_UNSIGNED_BYTE, .count=2u, .typeSize=sizeof(GLubyte), .offset=offset };
case Light::VertexElementType::UByte4: return { .type=GL_UNSIGNED_BYTE, .count=4u, .typeSize=sizeof(GLubyte), .offset=offset };
/* int */
case VertexElementType::Int1: return { .type=GL_INT, .count=1u, .typeSize=sizeof(GLint), .offset=offset };
case VertexElementType::Int2: return { .type=GL_INT, .count=2u, .typeSize=sizeof(GLint), .offset=offset };
case VertexElementType::Int3: return { .type=GL_INT, .count=3u, .typeSize=sizeof(GLint), .offset=offset };
case VertexElementType::Int4: return { .type=GL_INT, .count=4u, .typeSize=sizeof(GLint), .offset=offset };
/* uint */
case VertexElementType::UInt1: return { .type=GL_UNSIGNED_INT, .count=1u, .typeSize=sizeof(GLuint), .offset=offset };
case VertexElementType::UInt2: return { .type=GL_UNSIGNED_INT, .count=2u, .typeSize=sizeof(GLuint), .offset=offset };
case VertexElementType::UInt3: return { .type=GL_UNSIGNED_INT, .count=3u, .typeSize=sizeof(GLuint), .offset=offset };
case VertexElementType::UInt4: return { .type=GL_UNSIGNED_INT, .count=4u, .typeSize=sizeof(GLuint), .offset=offset };
/* float */
case VertexElementType::Float1: return { .type=GL_FLOAT, .count=1u, .typeSize=sizeof(GLfloat), .offset=offset };
case VertexElementType::Float2: return { .type=GL_FLOAT, .count=2u, .typeSize=sizeof(GLfloat), .offset=offset };
case VertexElementType::Float3: return { .type=GL_FLOAT, .count=3u, .typeSize=sizeof(GLfloat), .offset=offset };
case VertexElementType::Float4: return { .type=GL_FLOAT, .count=4u, .typeSize=sizeof(GLfloat), .offset=offset };
default: lt_assert(false, "Invalid 'VertexElementType'"); return {};
}
}
} // namespace Light